dl-Methyl jasmonate is an ingredient of jasmine oil which is used for preparing perfume compositions and has the following structure ##STR1## wherein the stereochemistry of the two aliphatic substituents on the cyclopentanone ring is trans. The 2-pentenyl double bond has the cis-configuration.
Syntheses of methyl jasmonate and of related 2-alkyl- and 2-alkenyl-3-oxo-cyclopentaneacetic acid lower alkyl esters have been reported in the chemical literature; E. Demole et al., Helv. Chim. Acta, 45, 692 (1962); K. Sisido et al., J. Org. Chem. 34 (9), 2661 (1969); Belgian Patent Nos. 628,779 and 791,801; and Swiss Patent No. 490,313.